Polyvinyl chloride compositions

ABSTRACT

A polyvinyl chloride composition having polyvinyl chloride resin and a plasticizer ester selected from di-butyl terephthalate, di-isobutyl terephthalate, or mixtures thereof.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No. 11/202,543 filed on Aug. 12, 2005, the disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

This invention pertains to novel polyvinyl chloride compositions. More particularly, this invention pertains to novel compositions containing an intimate admixture of polyvinyl chloride and an ester plasticizer. More particularly, the present invention pertains to polyvinyl chloride compositions including a plasticizer selected from di-butyl terephthalate, di-isobutyl terephthalate and mixtures thereof.

BACKGROUND OF THE INVENTION

Polyvinyl chloride (commonly referred to as “PVC”) has been used for a number of years in the manufacture of soft, flexible films for food packaging, in molded rigid products (such as pipes, fibers, upholstery and bristles), and in a variety of other products, including electric wire and cable-coverings, film finishes for textiles, raincoats, belting, gaskets and shoe soles. A variety of plasticizers have been used to produce flexible PVC articles. The plasticizer compounds differ in many respects but all of them must possess certain characteristics. For example, the plasticizer compound must be compatible with the PVC resin and render the PVC more flexible and/or softer. In PVC, the plasticizer also assists in the fusion of the PVC formulation to produce the final article. In the typical fusion process, the PVC resin particles dissolve and/or break apart, intermingle with all the other additives to produce the final homogenously mixed material. Plasticizers that have a high affinity for PVC resin resulting in very quick fusion are called high-solvating plasticizers. Fusion in dry blends is accomplished by a combination of stress and temperature. Fusion in plastisols occurs mainly by temperature. There are a number of chemical classes of high-solvating plasticizers such as benzoates, butyl benzyl phthalate, dihexyl phthalate, and others. High-solvating plasticizers provide faster fusion allowing fusion to occur at lower temperatures or to occur faster at a given temperature. A disadvantage for plastisols is high solvating plasticizers are typically not as stable to viscosity increases as general purpose plasticizers.

BRIEF SUMMARY IF THE INVENTION

We have found that di-butyl terephthalate (DBTP) and di-isobutyl terephthalate (DIBTP) are high-solvating plasticizers for PVC resins and provide advantages compared to other high solvating plasticizers when incorporated into PVC resins. DBTP-containing PVC compositions have better low temperature properties and exhibits stain resistance equivalent to PVC plasticized with benzoate esters (which are very stain resistant plasticizers) and better than other high solvating plasticizers such as butyl benzyl phthalate At the same time, DBTP-containing plastisols also are lower in viscosity and maintain this difference as the plastisol ages. The present invention thus provides a novel PVC composition comprising a PVC resin containing a plasticizing amount of di-butyl terephthalate, di-isobutyl terephthalate or a mixture thereof. The PVC compositions of the present invention have a variety of uses such as in adhesives and sealants, coated fabrics, wire and cable coatings, foams, footwear, gaskets, inks, cosmetics, and medical devices. PVC-based applications include floor coverings, wallpaper, roofing membranes, tubing, inks, and calendared film.

DETAILED DESCRIPTION

The composition of the present invention comprises a PVC resin and a plasticizer selected from di-butyl terephthalate, di-isobutyl terephthalate or a mixture thereof. As used herein, the term “PVC resin” means homopolymers of polyvinyl chloride resin(s), copolymers of polyvinyl chloride resin(s), and mixtures thereof. Copolymers of vinyl chloride are formed by the copolymerization of vinyl chloride and other monomers or monomer blends. Suitable monomers include vinyl acetate, ethylene, propylene, maleate, methacrylate, acrylate, high alcohol vinyl ester, urethane, chlorinated urethane, methylmethacrylate, and mixtures thereof. Examples of monomer blends include ethylene-vinyl acetate copolymer, acrylonitrile-butadiene-styrene terpolymer, acrylonitrile-butadiene copolymer, and mixtures thereof. The monomers or monomer blends may be present in an amount of up to 10 parts per hundred parts resin (the term “parts per hundred parts resin” is used herein to define the quantity of the components based on the weight of the resin and is abbreviated “PHR”).

The PVC resin component of the present invention has a degree of polymerization (DP) which is between 650 and 1600, preferably between 900 and 1100, and an inherent viscosity (IV) between 0.5 and 1.4 (based on ASTM D-1243). The PVC-based resin of the present invention may be formulated from a single PVC resin or a mixture of two or more different PVC resins. When two or more different PVC resins are used, the PVC resins preferably have degrees of polymerization which are relatively close in value. The di-butyl and/or di-isobutyl terephthalate plasticizer compounds may be used alone, together or they may be used in combination with additional plasticizers in the PVC composition. Examples of such additional plasticizers include, but are not limited to, dioctyl phthalate, di-2-ethyl hexyl phthalate, diisooctyl phthalate, diisononyl phthalate, di-linear nonyl phthalate, di-linear nonyl, undecyl phthalate, di-linear undecyl phthalate, diundecyl phthalate, diisodecylpthalate, C₆-C₁₀ straight-chain phthalates, C₇ linear phthalate, C₉ linear phthalate, C₁₁ linear phthalate, ditridecyl phthalate, undecyl dodecyl phthalate, di(2-propylheptyl phthalate), nonylundecyl phthalate, texanolbenzylphthalate, polyester phthalate, diallylphthalate, n-butylphthalyl-n-butyl glycosate, dicaprylphthalate, butylcyclohexyl phthalate, dicyclohexyl phthalate, butyl octyl phthalate, dioctyl terephthalate, di-2-ethyl hexyl terephthalate, dioctyl adipate, di-2-ethyl hexyl adipate, diisonyl adipate, diisooctyl adipate, diisodecyl adipate, di tridecyl adipate, dibutoxyethyl adipate, dibutoxyethoxy adipate, di(noctyl, ndecyl)adipate, polyester adipate, poly glycol adipates, trioctyl trimellitate, tri-2-ethyl hexyl trimellitate, triisooctyl trimellitate, tri isononyl trimellitate, triisodecyl trimellitate, tri-n-hexyl trimellitate, dioctyl azelate, di-2-ethylhexyl glutarate, di-2-ethyl hexyl sebecate, dibutyl sebecate, dibutoxyethyl sebecate, triethyl citrate, acetyl triethyl citrate, tri-n-butyl citrate, acetylri-n-butyl citrate, acetyltri-n-hexyl citrate, n-butyl tri-n-hexyl citrate, isononyl benzoate, isodecyl benzoate, 1,4 cyclohexane dimethanol dibenzoate, 2,2,4 trimethyl-1,3 pentane diol dibenzoate, 2,2,-dimethyl-1,3 propanediol dibenzoate, C₁₀-C₂₁ alkane phenol esters or alkyl sulphonic phenol ester, acetic acid reaction products with fully hardened castor oil, pentaerythritol tetrabenzoate, glycerol tribenzoate, polypropylene glycol dibenzoate, triarylphosphates, diisononyl cyclohexane 1,2 dicarboxylate, polymers of adipic acid/phthalates/adipates/sebecates/ with glycols and often acid terminated, butyl benzyl phthalate, alkylbenzyl phthalate, C₇-C₉ butyl phthalate, diethylene glycol dibenzoate, di propylene glycol dibenzoate, 2-ethylhexyl benzoate, texanolbenzoate, ethylene glycol dibenzoate, propylene glycol dibenzoate, triethylene glycol dibenzoate, di-heptyl phthalate, dihexyl phthalate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, and mixtures thereof. The plasticizer or plasticizers are present in the compositions of the present invention in amounts ranging from about 20 to 800 PHR, more typically about 40 to 120 PHR, and most preferably from about 40 to 80 PHR. Di-butyl terephthalate and/or di-isobutyl terephthalate constitute from about 10 to 100 weight percent, preferably about 25 to 100 weight percent of the total plasticizer present in the compositions.

The compositions of the present invention may contain one or more stabilizers such as metal soaps, organic phosphites, epoxy compounds, tin stabilizers, and mixtures thereof. The stabilizers provide protection against deficient PVC homopolymerization and copolymerization, and functions to eliminate or retard the process of polymer degradation. The total amount of stabilizer present in the compositions ranges from 0.1 to 10 PHR, preferably from 1 to 7 PHR, and most preferably 2 to 5 PHR. Preferably, the stabilizer is a mixture of metal soaps and epoxy compounds, or a mixture of metal soaps, epoxy compounds and organic phosphites.

Metal soap stabilizers include zinc stearate, barium stearate, calcium stearate, cadmium stearate, barium ricinolate, calcium oleate, calcium laurelate, zinc octoate, and mixtures thereof. Preferably, the metal soap stabilizers are mixtures of barium stearate, zinc stearate and cadmium stearate. A preferred barium stearate/zinc stearate mixture is sold by Bearlocher (Chemgrade UBZ-791), and preferred calcium stearate/zinc stearate and barium stearate/cadmium stearate mixtures are sold by Azko Interstab. (CZ-19A and BC-103L, respectively). Epoxy compound stabilizers include epoxy soybean oil, e.g., Srapex 6.8, ESO, epoxy linseed oil, epoxy polybutadiene, epoxy methylstearate, epoxy stearate, epoxy ethylhexyl stearate, epoxy stearyl stearate, epoxy propyl isocyanalate 3-(2-case INO)-1,2-epoxy propane, bis-phenol A diglycidyl ether, vinyl dicyclohexanediepoxide, 2,2-bis-(4-hydroxyphenol) propane and epichlorohydrine condensation copolymeration, and mixtures thereof. Organic phosphite stabilizers include diphenyldecyl phosphite, triphenyl phosphite, tris-nonylphenyl phosphite, tri-steareal phosphite, octyldiphenyl phosphite, and mixtures thereof. Tin stabilizers include tin dilaurate, dibutyl tin maleate, organic tin mercaptide and organic tin sulfonic amide, and mixtures thereof.

The above stabilizers may be used individually or in any combination. Preferably, the stabilizers are mixtures of zinc stearate, barium stearate, calcium stearate, and epoxy compounds. A preferred epoxy stabilizer is epoxy soybean oil. In addition, organic phosphites may be used in conjunction with the zinc stearate, barium stearate, cadmium stearate, and epoxy compound mixtures. Particularly preferred stabilizer mixtures are barium stearate/zinc stearate and epoxy soybean oil, calcium stearate/zinc stearate and epoxy soybean oil, and barium stearate/cadmium stearate and epoxy soybean oil. In addition to PVC or a PVC-based resin, the di-butyl and/or di-isobutyl terephthalate plasticizer compounds primary plasticizer(s) and optional stabilizer(s), the compositions of the present invention may include additional additives, such as anti-static agents, anti-fogging agents, ultra-violet inhibitors, anti-oxidants, light stabilizers, fire retardants, pigments, and mixtures thereof. These additives are generally known in the art and may be present in the compositions in an amount sufficient to impart the desired property (generally below 10 PHR). Anti-static and anti-fogging agents include sorbitan fatty ester, sorbitol fatty ester, glycerine fatty

Di-butyl terephthalate (DBTP) and di-isobutyl terephthalate (DIBTP) have been found to be high solvating plasticizers for PVC and PVC-based polymeric materials. High solvating plasticizers such as butyl benzyl phthalate fuse at a faster rate/lower temperature than do general purpose plasticizers such as di(2-ethylhexyl)phthalate (DOP) and di(isononyl)phthalate (DINP). Plastisols are dispersions of certain polyvinyl chloride resins of very small to medium particle size, e.g., average particle size of about 1 to 100 microns, in liquid plasticizers. Dry plasticized PVC compositions typically are prepared for PVC resins having large particle size, e.g., average particle size of about 100 to 400 microns. Viscosity is an important property for the processing of plastisol PVC compositions. The application often dictates the absolute value. Excessively high viscosity can cause problems pumping and filling mold features. Too low viscosity may result in material run off and give parts or articles that are too thin. Viscosity stability also is important because if the viscosity increases too fast, the time for using the plastisol may be insufficient. Problems resulting from high viscosity in plastisols include poor filling of molds, difficulty in coating to given thicknesses, inability to pump the plastisol, and eventually premature gelling of the composition. When parts are made on a volume basis, lower density is advantageous since more parts per weight of PVC may be produced.

Plastisol formulations of our novel compositions may be prepared by mixing the liquid ingredients together using a high intensity mixer, e.g., a Cowles mixer, or a low intensity mixer, e.g., a Hobart mixer. The PVC resin and other solid ingredients are added over a short time period with mixing in either a high or low intensity mixers and the resultant dispersion often is deaerated under vacuum or other conditions. The plastisol then may be fused under a number of different heat conditions such as knife coated to a certain thickness and fused in an oven at varying temperature, in heated molds, in cold molds that are subsequently heated, and similar methods. Once fused, physical properties of the plastisol may be determined.

Dry formulations of the PVC compositions may be prepared by combining the solid ingredients and mixing them in a Henschel mixer. The liquid ingredients then are slowly added. The mixture is blended until a temperature of about 88° C. is reached, at which temperature PVC is below its fusion temperature. This procedure produced a free-flowing powder of PVC particles having the other ingredients absorbed therein. The free-flowing powder then may be fused on a 2 roll mill at a temperature of about 140 to 150° C. to produce a fused PVC sheet.

EXAMPLES

The preparation and properties of the compositions provided by the present invention are further illustrated by the following examples 1-3. The compositions of the following examples were prepared by mixing the liquid ingredients together using a high intensity mixer, e.g., a Cowles mixer, or a low intensity mixer, e.g., a Hobart mixer and mixed sufficiently to produce a substantially homogeneous mixture. The PVC resin and other solid ingredients are added over a short time period with mixing in either a high or low intensity mixers and the resultant dispersion often is deaerated under vacuum or other conditions. The plastisol was placed in a 1778 micron (70 mil) mold and fused in an oven at 175 to 190° C. and test bars were cut from the fused sheets.

Modulus of elasticity and the tensile strength are measured according to ASTM D142. Fusion was done using ASTM D 2538 (fusion properties and gel properties are determined with this test). The elongation, modulus of elasticity and the tensile strength are measured according to ASTM D412. The tear resistance was measured according to ASTM D624, and the brittleness temperature was measured according to ASTM D746. Brookfield viscosity (centipoises) was determined according to ASTM D1824, typically at ambient temperature or 25° C. Unless specified otherwise, spindle #5 was used in the Brookfield viscosity measurements. Tear resistance was measured according to ASTM D624, brittleness temperature was measured according to ASTM D746, chemical extractions were D1239, carbon extraction D1203, specific gravity D792, and shore A hardness D2240.

Example 1 and Comparative Example C-1

Using the above-described procedure, two compositions were prepared from PVC (Oxy 75HC resin supplied by Oxychem), 70 PHR plasticizer, 2 PHR epoxidized soybean oil (Drapex 6.8 supplied by Crompton-Witco) and 2 PHR of a mixed metal stabilizer (Akcrostab LT 4798 supplied by Akros Chemicals). In the first composition, the plasticizer was a 75:25 by weight blend of dioctal terephthalate (DOTP) and DBTP (Example 1). In the second composition, the plasticizer was a 75:25 by weight blend of DOTP and diethylene glycol dibenzoate (Example C-1).

The Brookfield viscosity, fusion and gel properties of the two compositions were determined and are set forth in Table I. The Brookfield viscosity was determined for 1 hour and 24 hours at 2.5 revolutions per minute (RPM) and 20 RPM. The viscosity values are centipoise, the fusion and gel time is given in minutes:seconds, fusion and gel temperature is given in ° F./° C., fusion and gel torque is given in meters*gram

TABLE I Example C-1 1 Brookfield Viscosity  1 hour @ 2.5 RPM 3680 2240  1 hour @ 20 RPM 2400 1700 24 hours @ 2.5 RPM 7450 6650 Fusion Time 18:00 18:23 Fusion Temp 266/130 269/131 Fusion Torque 815 761 Gel Time  8:45  9:11 Gel Temp 161/72  165/74  Gel Torque 11 11

Various physical properties for the two compositions were determined using the procedures described above. These physical properties are set forth in Table II. The values in parentheses are standard deviations.

TABLE II Example C-1 1_ Tensile Strength, MPa 8.6(2.1) 12.4(1.4)  Modulus at 100% Elong, MPa 5.1(0.2) 5.0(0.1) Elongation at Brk, % 198(64)  345(53)  Shore A Hardness 64(2)  65(1)  Tear Resistance, kN/M 40.7(3.9)  43.8(2.3)  Specific Gravity, g/cm³ 1.205(0.003) 1.1856(0.001)  Brittlenesss Temp, ° C. −41 −46 Cottonseed Oil Extractionl, % loss 21.3(0.6)  17.9(0.9)  Hexane Extraction, % loss 34.6(3.2)  27.4(1.4)  1% Soap Water Extraction, % loss 2.9(0.5) −0.2(0.2)* Carbon Extraction, % loss 2.5(0.1) 5.5(1.3)

Example 2 and Comparative Examples C-2 and C-3

Using the above-described procedure, three compositions were prepared from a 70:30 by weight mixture of 2 different PVC resins: 70 parts Oxy 6547 resin and 30 parts Oxy 625 resin, 70 PHR plasticizer, 3 PHR epoxidized soybean oil (Drapex 6.8) and 2 PHR of a mixed metal stabilizer (Akcrostab 4398 supplied by Akcros Chemical). The Oxy230 PVC powder has an internal viscosity IV of 0.95 and a molecular weight factor K of 68. In the first composition, the plasticizer was DBTP (Example 2); in the second composition, the plasticizer was diethylene glycol dibenzoate (Example C-2); and in the third composition, the plasticizer was butyl benzyl phthalate (Example C-3).

The Brookfield viscosity, fusion and gel properties of the two compositions were determined and are set forth in Table III. The Brookfield viscosity was determined for 1 hour and 24 hours at 2.5 RPM and 20 RPM. The viscosity values are centapoise, the fusion and gel time is given in minutes:seconds, fusion and gel temperature is given in ° F./° C., fusion and gel torque is given in meters*gram

TABLE III Example 2 C-2 C-3 Brookfield Viscosity  1 hour @ 2.5 RPM 1650 2550 1950  1 hour @ 20 RPM 1368 2531 1837 24 hours @ 2.5 RPM 3300 5400 3000 24 hours @ 20 RPM 2493 4800 2625 Fusion Time 10:09 10:02 10:12 Fusion Temp 178/81 176/80 179/82 Fusion Torque 821 956 857 Gel Time  5:42  5:17  6:20 Gel Temp 126/52 120/49 133/56 Gel Torque 5 5 5

Various physical properties for the three compositions were determined using the procedures described above. These physical properties are set forth in Table IV.

TABLE IV Example 2 C-2 C-3 Tensile Strength, MPa 11.7(0.4)  14.6(0.4)  15.7(1.1)  Modulus at 100% Elong, MPa 4.5(0.5) 5.3(0.1) 5.4(0.2) Elongation at Break, % 361(36)  401(10)  383(18)  Shore A Hardness 53(3)  67(1)  56(4)  Tear Resis, kN/M 32.9(2.6)  43.1(1.6)  41.0(4.4)  Specific Gravity, g/cm³ 1.228(0.009) 1.292(0.001) 1.278(0.006) Tear Force, N 45(10) 31(6)  53(9)  Brittleness Temp, ° C. −45 −24 −28

Example 3 and Comparative Example C-4

Using the above-described procedure, two compositions were prepared from a 80:20 by weight mixture of 2 different PVC resins: 80 parts Oxy 75HC resin and 20 parts Oxy 625 resin, 60 PHR plasticizer, 3 PHR epoxidized soybean oil (Drapex 6.8) and 2 PHR of a mixed metal stabilizer (Akrostab 4398), In the first composition, the plasticizer was DBTP (Example 3) and in the second composition, the plasticizer was butyl benzyl phthalate (Example C-4).

The Brookfield viscosity, fusion and gel properties of the two compositions were determined and are set forth in Table V. The Brookfield viscosity was determined for 1 hour at 2.5 RPM and 20 RPM. The viscosity values are centipoise, the fusion and gel time is given in minutes:seconds, fusion and gel temperature is given in ° F./° C., fusion and gel torque is given in meters*gram

TABLE V Example 3 C-4 Brookfield Viscosity 1 hour @ 2.5 RPM 3920 4720 1 hour @ 20 RPM 1880 2990 Fusion Time 7:56 8:04 Fusion Temp 163/73 161/72 Fusion Torque 2033.4 1821.0 Gel Time 4:43 5:23 Gel Temp 119/48 126/52 Gel Torque 16 15

Various physical properties for the two compositions were determined using the procedures described above. These physical properties are set forth in Table VI.

TABLE VI Example Example 3 Example C-4 Tensile Strength, MPa 14.51(1.067) 16.62(1.512) Modulus at 100% Elong, MPa  4.48(0.068)  5.65(0.150) Elongation at Brk, % 401.5(24.28) 351.1(32.69) Shore A Hardness 61(2)  60(2)  Tear Resistance, kN/M 39.7(1.90) 49.7(3.38) Specific Gravity, g/cm³  1.2302(0.00251)  1.2719(0.00322) Tear Force, N 45.1(3.33) 39.3(4.55) Cottonseed Oil Extraction, % loss 3.5(0.3) 1.6(0.4) Hexane Extraction, % loss 15(3)  6(2) 1% Soap Water Extraction, % loss 0.70(0.02) 0.64(0.30) Carbon Extraction, % loss 8.2(0.7) 2.6(0.1)

Example 4 and 5 and Comparative Example C-5

Using the above-described procedure, three compositions were prepared from a PVC resin (Oxy 240F), 50 PHR plasticizer, 2 PHR epoxidized soybean oil (Drapex 6.8) and 2 PHR of a mixed metal stabilizer (Across LT 4798. In the first composition, the plasticizer was a 75:25 by weight blend of DOTP and diethylene glycol dibenzoate (Benzoflex 2-45 from Velsicol) (Example C-5); in the second composition, the plasticizer was a 75:25 blend of DOTP and DBTP (Example 4); and in the third composition, the plasticizer was a 75:25 blend of DOTP and DIBTP (Example 5).

The fusion and gel properties of the three compositions were determined and are set forth in Table VII. The fusion and gel times are given in minutes:seconds, fusion and gel temperature is given in ° F./° C., fusion and gel torque is given in meters*gram

TABLE VII Example Example C-5 Example 4 Example 5 Fusion Time 6:46 6:25 6:13 Fusion Temp 277/136 277/136 276/135 Fusion Torque 899 839 845 Gel Time 2:35 3:07 2:58 Gel Temp 263/128 264/129 265/129 Gel Torque 408 467 479

Various physical properties for the two compositions were determined using the procedures described above. These physical properties are set forth in Table VIII.

TABLE VIII Example Example C-5 Example 4 Example 5 Tensile Strength, 19.79(0.826) 19.16(0.661) 18.31(0.857) MPa Modulus at 100% 11.02(0.133) 10.20(0.217) 13.08(0.848) Elong, MPa Elongation at 307.7(30.58) 327.0(20.70) 197.0(12.15) Brk, % Shore A Hardness 77(2)  77(3)  78(2)  Tear Force, N 123.0(4.29)  127.3(9.85)  128.5(13.69) Tear Resistance, 76.7(2.97) 79.1(4.73) 78.2(6.80) kN/M Specific Gravity,  1.2516(0.00510)  1.2376(0.00398) 1.2358(0.00237) g/cm³ Brittleness −28 −33 −28 Temp, ° C. 1% Soapy water Loss 0.42 Gain 0.02 Gain 0.04 extraction, % Cottonseed oil Loss 1.35 Loss 1.58 Loss 1.55 extraction, % Hexane Loss 5.69 Loss 21.96 Loss 21.50 extraction, % Carbon Loss 0.56 Loss 1.52 Loss 2.12 extraction, %

Example 6 and Comparative Examples C-6 and C-7

Using the above-described procedure, three compositions were prepared from a blend of PVC resins consisting of 91.4 parts by weight Oxy 80 HC PVC and 8.6 parts by weight PVC blending resin Oxy 567 (both supplied by Oxychem), 30 PHR plasticizer, 17 PHR TXIB (2,2,4-trimethyl-1,3-pentanediol diisobutyrate), 8 PHR mineral spirits, 3 PHR poly(ethylene glycol) 400 and 5 PHR of a mixed metal stabilizer (Akrostab 4798), In the first composition, the plasticizer was a mixed benzoate plasticizer blend (Benzoflex 6000 from Velsicol) (Example C-6); in the second composition, the plasticizer was butyl benzyl phthalate (Santicizer 160 supplied by Ferro (Example C-7); and in the third composition, the plasticizer was DBTP (Example 6). The plastisol were placed in a 508 micron (20 mil) mold and fused in oven at 20.4° C. (400° F.) for 2 minutes.

The compositions were evaluated for stain resistance by applying to (staining) the fused sheets prepared from the compositions brown color paste shoe polish, a 2 percent by weight solution of iodine in ethanol, and blue Magic Marker. The staining materials were allowed to remain on the fused sheets for periods of time of 1 hour and 24 hours and then were removed by rubbing with a cotton cloth and a cleaning solution. For both the shoe polish and marker, mineral spirits were used. For the Iodine, isopropanol followed by mineral spirits were used. The stains remaining on the fused sheets then were evaluated and rated according to the following rating system: 5=severe staining, 4=considerable staining, 3=moderate staining, 2=slight staining and 1=no staining. The results of the staining evaluations values for the 1-hour and 24-hour tests are set forth in Tables IX and X, respectively.

TABLE IX Staining Materials Example C-6 Example C-7 Example 6 Shoe Polish 3 4 4 Iodine 3 4 3 Blue Marker 3 4 3

TABLE X Staining Materials Example C-6 Example C-7 Example 6 Shoe Polish 3 4 4 Iodine 3 4 3 Blue Marker 3 4 3

Having described the invention in detail, those skilled in the art will appreciate that modifications may be made to the various aspects of the invention without departing from the scope and spirit of the invention disclosed and described herein. It is, therefore, not intended that the scope of the invention be limited to the specific embodiments illustrated and described but rather it is intended that the scope of the present invention be determined by the appended claims and their equivalents. Moreover, all patents, patent applications, publications, and literature references presented herein are incorporated by reference in their entirety for any disclosure pertinent to the practice of this invention. 

We claim:
 1. A free-flowing powder composition comprising PVC resin particles, a plasticizer selected from the group consisting of di-butyl terephthalate, di-isobutyl terephthalate and mixtures thereof, and at least one additional plasticizer selected from the group consisting of di-2-ethylhexyl terephthalate, triethyl citrate, acetyl triethyl citrate, tri-n-butyl citrate, acetytri-n-butyl citrate, acetyltri-n-hexyl citrate, n-butyl tri-n-hexyl citrate, diisononyl phthalate, diisononyl cyclohexane 1,2-dicarboxylate, dioctyl terephthalate, tri-2-ethylhexyl trimellitate, di-2-propylheptyl phthalate, diisodecyl phthalate, diisoundecyl phthalate, ditridecyl phthalate, triisononyl trimellitate, and di-2-ethylhexyl adipate; wherein the plasticizers are present in the composition in an amount from about 20 to 120 parts plasticizer per 100 parts PVC resin, and wherein at least 10 weight percent of the total plasticizer is di-butyl terephthalate, di-isobutyl terephthalate or a mixture thereof.
 2. The free-flowing powder composition of claim 1 wherein the plasticizer is present in the composition in an amount from about 40 to 120 parts plasticizer per 100 parts PVC resin.
 3. The free-flowing powder composition of claim 1 wherein the plasticizer is present in the composition in an amount from about 40 to 80 parts plasticizer per 100 parts PVC resin.
 4. The free-flowing powder composition of claim 1 wherein at least 25 weight percent of the plasticizer is di-butyl terephthalate, di-isobutyl terephthalate or a mixture thereof.
 5. The free-flowing powder composition of claim 1, wherein the PVC resin has a degree of polymerization between 650 and 1600 and an inherent viscosity between 0.5 and 1.4 based on ASTM D-1243.
 6. The free-flowing powder composition of claim 1, wherein the composition further comprises one or more additional components selected from stabilizers, anti-static agents, anti-fogging agents, ultra-violet inhibitors, anti-oxidants, light stabilizers, fire retardants, pigments, or combinations of two or more of the foregoing.
 7. The free-flowing powder composition of claim 1 wherein the at least one additional plasticizer selected from di-2-ethylhexyl terephthalate, diisononyl phthalate, diisononyl cyclohexane 1,2-dicarboxylate, di-2-propylheptyl phthalate, and di-2-ethylhexyl adipate.
 8. The free-flowing powder composition of claim 7 wherein at least 25 weight percent of said plasticizer is di-butyl terephthalate, di-isobutyl terephthalate or a mixture thereof.
 9. The free-flowing powder composition of claim 1 wherein the at least one additional plasticizer is selected from the group consisting of di-2-ethylhexyl terephthalate, diisononyl phthalate, and diisononyl cyclohexane 1,2-dicarboxylate.
 10. The free-flowing powder composition of claim 9 wherein at least 25 weight percent of said plasticizer is di-butyl terephthalate, di-isobutyl terephthalate or a mixture thereof.
 11. A method comprising applying heat to the free-flowing powder composition of claim 1 under conditions effective to fuse the free-flowing powder composition.
 12. A fused polyvinyl chloride composition made by the method of claim
 11. 13. An article comprising the fused polyvinyl chloride composition of claim
 12. 14. The article of claim 13, wherein the article is an adhesive, a sealant, a coated fabric, a wire coating, a cable coating, a foam, a footwear, a gasket, an ink, a cosmetic, a medical device, a floor covering, a wallpaper, a roofing membrane, tubing or a calendared film.
 15. A free-flowing powder composition comprising PVC resin particles, di-butyl terephthalate, and at least one additional plasticizer selected from the group consisting of di-2-ethylhexyl terephthalate, triethyl citrate, acetyl triethyl citrate, tri-n-butyl citrate, acetytri-n-butyl citrate, acetyltri-n-hexyl citrate, n-butyl tri-n-hexyl citrate, diisononyl phthalate, diisononyl cyclohexane 1,2-dicarboxylate, dioctyl terephthalate, tri-2-ethylhexyl trimellitate, di-2-propylheptyl phthalate, diisodecyl phthalate, diisoundecyl phthalate, ditridecyl phthalate, triisononyl trimellitate, and di-2-ethylhexyl adipate; wherein the plasticizers are present in the composition in an amount from about 20 to 120 parts plasticizer per 100 parts PVC resin, and wherein at least 10 weight percent of the total plasticizer is di-butyl terephthalate.
 16. The free-flowing powder composition of claim 15 wherein the plasticizer is present in the composition in an amount from about 40 to 120 parts plasticizer per 100 parts PVC resin.
 17. The free-flowing powder composition of claim 15 wherein the plasticizer is present in the composition in an amount from about 40 to 80 parts plasticizer per 100 parts PVC resin.
 18. The free-flowing powder composition of claim 15 wherein at least 25 weight percent of said plasticizer is di-butyl terephthalate, di-isobutyl terephthalate or a mixture thereof.
 19. The free-flowing powder composition of claim 15 wherein the at least one additional plasticizer is selected from the group consisting of di-2-ethylhexyl terephthalate, diisononyl phthalate, diisononyl cyclohexane 1,2-dicarboxylate, di-2-propylheptyl phthalate, and di-2-ethylhexyl adipate.
 20. The free-flowing powder composition of claim 19 wherein at least 25 weight percent of said plasticizer is di-butyl terephthalate, di-isobutyl terephthalate or a mixture thereof.
 21. The free-flowing powder composition of claim 15 wherein the at least one additional plasticizer is selected from the group consisting of di-2-ethylhexyl terephthalate, diisononyl phthalate, and diisononyl cyclohexane 1,2-dicarboxylate.
 22. The free-flowing powder composition of claim 21 wherein at least 25 weight percent of said plasticizer is di-butyl terephthalate, di-isobutyl terephthalate or a mixture thereof.
 23. A method comprising applying heat to the free-flowing powder composition of claim 15 under conditions effective to fuse the free-flowing powder composition.
 24. A fused polyvinyl chloride composition made by the method of claim
 23. 25. An article comprising the fused polyvinyl chloride composition of claim
 24. 26. The article of claim 25, wherein the article is an adhesive, a sealant, a coated fabric, a wire coating, a cable coating, a foam, a footwear, a gasket, an ink, a cosmetic, a medical device, a floor covering, a wallpaper, a roofing membrane, tubing or a calendared film. 